(disclaimer: not diagnosed so there's always the chance that I'm not bipolar although I think that I am..)

I've always found that weed calms me down. Sorta zombiefies me sometimes actually. It slows my thoughts down and I can only focus on one thing at a time. Which usually means I'm very focused on who I'm talking to, or what I'm watching, or listening to what's being sad, or making sure I'm not going to drop my glass.... that I don't have the mental energy to even be sad or stressed out.

Alcohol, on the other hand, makes me hyperactive.